Pavel Kolpakov

There are currently 7 manufacturers on the market that produce TTL triggers: UWTechnics, Nauticam, TRT, Ikelite, AOI, Inon, Backscatter. But only 1 of these 7 manufacturers uses online updating. This is not accidental. But if online updating is the main criterion for you among all the characteristics and functions, you can choose it, why not. This is quite normal. Other people have other, more important criteria. And that's okay too.

Of course not. It does not work this way. Our TTL-Converter has 9 different type ttl-profiles in the firmware, each profile can be set by the rotary switch. Totally for Sony, Canon, Nikon and Olympus there are 36 different ttl-profiles in our firmware. Those profiles includes almost all varieties of ttl-profiles which are in use nowadays among the underwater strobes. Most of new strobes appear on the market have the same or very similar ttl-profiles as existing in the firmware. So, In most of cases client does not need to update the firmware when a new strobe appears on the market. He just need to ask us about the information, - what ttl-profile should be set by the onboard rotary switch. We update the firmware now only if actually a new ttl-profile strobe has appeared, for example in 2025 it may be 1-2 times or so. Or may be not at all in 2025, unless a fundamentally new ttl-profile appears.

We issue the firmware update only if we add a new strobe model which did not exist before on the market. And there is no any other reason for our TTL-Converter update. Currently it is necessary to send the product to the factory. In future we plan to make an online update too.

Do you mean synchronization for 4 strobes installed on the housing arms? You can use 2 pcs of dual optical fiber cable for 4 strobes synchronization. If you mean 2 strobes on the housing + 1-2 strobes installed on the bottom (at long distance from the housing), we can also make long length optical fiber cables (single, or dual), no problem.

The firmware is the same. The difference is only a metal body. External TTL Converters were made with the metal body to improve the mechanical protection and simplify the installation. If you already have an internal unit and everything is Ok, you don't need to change it.

Hi Jorg, We probably can update your TTL-converter, if hardwire allows the OPTIMA strobe support. We will check. Let's be in contact by messenger or e-mail. What slave mode do you mean, probably the triggering from other strobes? We plan to produce an external sensor (screws to the strobe input) for creative shooting with few strobes, which provides a wide radiation pattern and high sensitivity to pulse flash, but totally resistant to sunlight and torches. Such device electronics is already developed by us. This task will be covered very effectively.

We have different strobes in plan for future. Some of them will be without video light.

The strobes you listed are very worthy products. I don't discuss products from other manufacturers, it is not my task, sorry. I can only tell photographers about our own HSS system of the flash OPTIMA-10000 and about the essence of the HSS flash lighting in general. The principles of normal flash synchronization and HSS-flash synchronization are explained in the picture below: At slow shutter speeds (up to 1/250s) the normal usual synchronization is in effect - the flash fires once at the moment of the fully open mechanical shutter window, full energy flash usually lasts 1-2 milliseconds. This is called the normal flash synchronization, or "X-synchronization". But at ultra fast shutter speeds (faster than 1/250s) the shutter window no longer opens completely, such a moment does not exist at all, it is a narrow open strip moving along the frame during 5 milliseconds. Here only HSS synchronization is possible, - the strobe makes many small quickly following flashes (the base frequency is usually about 30 kHz) firing during 5 milliseconds, thus exposing the entire frame. And the faster the shutter speed, the narrower the open strip. The method of adjusting the intensity of HSS flash illumination usually is to change the frequency. The main problem with the HSS flash lighting is considered to be the so-called "Banding". These are alternating dark and light narrow stripes on the image. The reason is the parasitic interaction of the pulsations of the HSS flash and the camera shutter work. With an increase in shutter speed, banding increases, sometimes at speeds closer to 1/8000 it becomes unacceptable for shooting. Banding is very dependent on the camera and flash model. With one camera model it is more noticeable, with another less. The problem of banding at the global level in photographic equipment has not yet been solved, even in land photography. Manufacturers of photographic equipment are struggling with this effect, but with varying success. Our strobe OPTIMA-10000 has another HSS frequency and completely different method of HSS flash intensity adjustment, than other underwater strobes. It was our own development. Developing our OPTIMA-1000, we performed hundreds of experiments related to HSS, as a result of which we optimized the electronic components, parameters adjustments and firmware, related to the operation in HSS mode in order to minimize the banding effect. Currently, testing the HSS flash with the camera models we have in stock (7 camera models, including Nikon, Canon, Sony and Olympus), - there is no banding, the image is absolutely clear even at 1/8000. Of course, banding may appear with some other cameras that we do not have in stock, so we plan to gradually test all other cameras popular in underwater photography to confirm the effect. We will publish the results.

We are preparing TTL/HSS profile for TTL-Converters now for OPTIMA-10000 support.

The weight is 230g in the fresh water.

Chris, thank you! The Ikelite versions of TTL-Converter (M16 and 1/2UNF) have a slightly different o-ring sealing than others and need a nut, the same nut as Ikelite bulkhead has. The nut usage requires much longer length of rear threaded part, than Isotta. Also, Ikelite version TTL-Converter has a lower overall height of external part of the body to reduce the shoulder of external impacts and avoid damage to the plastic housing. Isotta version has some greater height of down external part of the body because some housing controls or protrusions are situated too close to the threaded M16 hole. Sometimes, who knows, It may be possible to install Ikelite M16 version Converter on the Isotta housing, but i am not sure, and it will require the concrete housing check. So, Isotta and Ikelite versions of TTL-Converter are different in the rear part of the body. We will publish all versions soon, you will see the difference on the pictures.

This is a camera menu for external flash control. TTL-Converter provides intellectual communication with the camera, including the menu options. The Canon version menu is shown on the pictures above. TTL-Converter even saves the latest Canon menu settings in it's non-volatile memory (for the user's convenience), and then loads them into the camera the next time the TTL-Converter is connected. UWTechnics produces such TTL-Converters for Nikon, Canon, Sony and Olympus. Nikon DSLR cameras are supported of course.

There is no any contradiction. The continuous shooting is actually available up to 120 fps using this strobe and UWTechnics TTL-Converter. The recycling time after full dump is actually 0.8 sec. The maximum 120 fps speed of course cannot be reached at the 150 Ws full power in each of 120 flashes during 1 second. Energy saved in capacitors is only 150 Joules. Strobe does not recharge at such speed at all (between such fast 120 flashes). So, you have to divide the available energy to the quantity of flashes. The 120 fps speed can be reached at small flash power, like 1/125. And UWTechnics TTL-Converter new firmware supports such continuous shooting speed with this strobe, for example with Sony A9 III camera. At such speed it can be used for any special macro tasks or so. But of course, 120fps would be extremely rare usage anyway. In reality we use up to 15 fps in underwater photography, in most of cases the 2-3 fps is enough.

Yes, this device was specially developed to simplify the installation and improve the mechanical protection.

Thank you, Tim. Subal threaded holes usually are situated too close to the central protrusion on the top of the housing, it would be impossible to install such device, but only bulkheads. Currently i see only the following housings acceptable for the External TTL-Converter installation: Nauticam, Marelux, Sea&Sea, Aquatica, Isotta, Ikelite, Seafrogs.

Underwater Technics company has announced new production line: External TTL Converters (for Sony, Canon, Nikon and Olympus). Mass production starts in March-2025. Product is made in sealed metal body, it has very simple and universal installation, - into the threaded hole on the top of the housing, very nice protection from water and from mechanical damages. Battery CR2032 can be easy replaced, one time per few years. External TTL Converter is available in few versions, for the following underwater housings: - M16 thread for Nauticam, Marelux, Seafrogs aluminum; - M16 thread for Isotta; - M24 thread for Marelux, Aquatica, Seafrogs aluminum; - M16 thread for Ikelite; - 1/2"UNF20 for Ikelite; - M12 for Seafrogs plastic housings. Product has the following features: - Switching TTL/M/HSS modes by camera menu, - Flash synchronization at 1-st / 2-nd curtain by menu, - TTL flash exposure compensation (+/-) adjustment by menu, - Manual flash power adjustment by menu 1/125...Full (in M mode), - HSS ultra fast shutter speeds up to 1/8000s, - Continuos shooting, - Battery life: 3 years of continuous work, - Automatic ON/OFF. No any mechanical switch is needed. - Supported strobes: Inon, Marelux, Retra, Sea&Sea, Underwater Technics. Here are the photos of pre-production samples:

Underwater Technics company (Taiwan) has announced OPTIMA-10000 underwater strobe with 10 000 lumen video light. Mass production starts in July-2025. New strobe has the following features: - Fine TTL exposure accuracy, supported by Underwater Technics TTL-Converters. - Fine HSS exposure quality (no any banding at shutter speeds up to 1/8000s)! - Circular shape flash tube provides a very uniform lighting on the whole area of the shot, especially in combination with the spherical dome, - Extremely fast strobe recycling - 0.8 sec (after full dump)! - Intellectual flash control is available by camera menu via UWTechnics TTL-Converter, - Continuos shooting up to 120 fps (!), using UWTechnics TTL-Converter, - Body and all parts are made of hard-anodized aluminum alloy, there are no any plastic parts. - Strobe power 150 Ws, Color Temperature 5500K, - Pilot light 600 lumen with Auto-Off function during the flash, - Video light 10 000 lumen, CRI 92, Color Temperature 5000K. - Battery construction incorporates 4 x 18650 cells, balancing and safety electronics. - Strobe weight (without battery) - 995g. - Battery weight - 215g. - Bayonet front mount for snoot, color filters and other external accessories. - Optional external reflectors (with bayonet mount) provide different beam width,- for different shooting tasks. - Snoot, reflectors, color filters and diffusers exist in production plan. Here are the photos of pre-production sample:

So, as i understand, the ONE UW-160 strobe does not have HSS synchronization by optical input, but only electrical. Then, there is no subject for the discussion about its optical sync.

Thank you for the information. As i see in the email, he simply has no information about UWT triggers compatibility, because he did not test. My thought, they are compatible. If i have a chance, i will test and publish this information.

Did anybody test ONE UW 160 strobe in HSS by optics? By the way, all other HSS-strobes work normally in HSS mode with UWTechnics triggers. Why do this strobe model would not work? I have doubts in this. Please tell me some details and where the information comes from.

Do you have 2 different housings (NA-R5C and NA-R6II)? If you think to reinstall the TTL Converter from one housing to another and back for many times, it will have a very short life. You have to install appropriate TTL Converter in each housing.

Hi Giancarlo, The reason was that you set a wrong Shutter type (probably "electronic" shutter). Please check the User Manual of TTL Converter, there written that necessary to set "Mechanical" shutter in the camera menu. All available sync speeds for Mechanical Shutter protocol are supported by TTL Converter. According to the Canon R5 camera Specifications, the maximum sync speed with Mechanical Shutter is 1/200. In the R7 camera Specifications it is 1/250. The maximum sync speed is limited automatically by the camera. This maximum sync speed is supported by TTL Converter of course, you can check.

You dived 100+ times after the last occurrence, and everything worked normally all 100 dives?

The loss of contact in this case is associated with a change in pressure, this is obvious. Generally speaking, this shouldn't have that much of an impact. But the contact is loose somewhere. I think it happens in the hot shoe. To clarify it some better, try diving without pumping out air at all, look at the effect. And before closing the housing push the shoe plug firmly into the socket until it stops, this is the most important thing. We can replace the TTL Converter of course, but the issue can be another.

I agree with Chris and Dave, i would also first of all assume a problem with the contacts in the hot shoe connection, and also check the buttons under pressure on the depth. The Sony MI shoe has 24 contacts, very thin and weak. Unfortunately, this new Sony MI shoe turned out to be quite unreliable for peripheral devices. However, the Sony company does not care about this. For a problem to occur, it is enough for just one necessary contact to become slightly deformed or corroded. Most often it is corrosion from sea air saturated with moisture and salt. If there is corrosion or salt deposits, the effect may appear from time to time, as well as with a slight displacement of the camera body under pressure (at depth). Sometimes salt deposits are invisible to the eye, but they are there. You need to thoroughly clean the shoe contacts with a cotton swab and alcohol. But the main thing here is that you need to firmly move the plug on the camera connector several times until it stops, back and forth, in order to mechanically remove possible corrosion. And one more piece of advice: every time before closing the housing, check how deep the plug is pushed into the shoe socket, since people often do not push this plug all the way in - this is the most common reason. If corrosion (or salt) has already occurred inside the plug, then you will not be able to clean it properly, and then only replacing it (plug with cable) will help. If you ultimately come to this conclusion, please contact us by email and we will send you a new plug. Less likely, but possible, is that at depth some button on the camera is pressed, preventing the shutter from being released. Well, this is easy to check - listen with your ear when that malfunction occurs, is the sound of the shutter release (mechanical shutter) heard at depth? The least possible reason, but still possible, is a deformation of PCB (mounted by 2 bolts), because of the mount. Try to mount the board significantly weaker, to prevent any possible deformation at the depth. Check if this has an effect.